1. Field of the Invention
This invention relates to an attachment for a router and, more particularly, to a router guide assembly and method which adapts a router for forming a cut parallel to an edge of a work piece.
2. The Prior Art
The conventional router is a high speed, hand-portable, electrically driven cutting tool useful for numerous woodworking or similar projects. The interchangability of cutting bits and hand portability readily adapts the router for numerous cutting projects including for example, cutting (1) intricate shapes, (2) scrollwork, (3) dado cuts, (4) mitering and the like. The depth of the cut produced by the router may also be controlled by adjusting the distance the cutting bit extends from the work face of the router. The router work face is pressed against the workpiece so as to obtain a uniform cutting depth.
The edge of the work face is circular and is concentric with the cutting bit. The edge of the work face, therefore, may be moved along a straight edge or guide for the purpose of forming a cut parallel to the guide which must be clamped to the workpiece at a distance corresponding to the distance between the edge of the circular work face and the cutting bit. The cutting bit thereby forms a cut in the workpiece corresponding to the contour provided by the edge of the guide. However, since the guide must be clamped directly to the workpiece at a distance corresponding approximately to the radius of the work face of the router, it is not possible to use this prior art technique for forming a mortise or the like in the edge of a door or similar narrow workpiece.
Numerous prior art devices are provided for forming a mortise in the edge of a workpiece and include U.S. Pat. Nos. 481,383; 931,552; 1,904,109; 3,087,520; 3,150,452; 3,392,762; 3,450,001; 3,559,704; and 3,612,118. Additionally, U.S. Pat. No. 3,099,299 discloses a guide attachment for a router wherein a vertical post is secured to the router so as to be coaxial with the cutting bit. The vertical post serves as a guide in cooperation with a template to cause the router to form a cut corresponding to the template. Other devices set forth in the foregoing patents relate to numerous types of jigs, guides and workholders useful in combination with a router or the like. However, a jig apparatus is generally expensive and limited as to the types of cuts that can be performed using the jig. Additionally, other attachments requiring securement to the work face of a router substantially restrict the router to performing a single type of cutting operation thereby greatly restricting the utility of the router.
In view of the foregoing, it would, therefore, be an advancement in the art to provide an attachable cutting guide assembly for a router which may be releasably attached to the work face of a router to readily adapt the router for forming a cut parallel to at least one edge of the workpiece. It would also be advantageous to provide a cutting guide apparatus and method whereby a router may be provided with a cutting guide assembly which accommodates being semipermanently mounted to the work face of a router and includes guide posts removably mounted thereto. Another advancement would be to provide a cutting guide assembly which accommodates router centering adjustment without removal of the cutting guide assembly from the router. Such an apparatus and method is disclosed in the present invention.